The Millston Union Church was built in 1904 as a municipally owned church building, available to rent from the town by members of any faith or denomination. Early use of the building was by itinerant preachers and circuit riders of multiple denominations.

The Millston Union Church is an important illustration of a small, early- twentieth-century, rural church building with elements of the Late Gothic Revival style. This municipal building, literally “the town church”, was Millston’s only church building since its construction until 1984. Additionally, the building is significant for its association with the community’s religious needs. When constructed in 1904, religious ornaments were noticeably absent from this building. This remained the case until 1960 when second-hand items, including an altar and pews, were purchased. In 1968 a lighted cross was installed atop the steeple, replacing a secular weathervane. Use of the Millston Union Church building has been sporadic over the years, but, just as it was in 1904, it continues to be owned by the town, administered by a board of trustees, and available for use by any faith or denomination.